20 BULLETIN 1375, IT. S. DEPARTMENT OF AGRICULTURE 
Milled rice, first and second head. — Use 100 grams of grain and 
150 cubic centimeters of oil. Place a glass-wool pad 2 inches in dia- 
meter and % inch thick in bottom of the flask. Care should be 
taken not to displace the glass wool. Extinguish the flame when 
the thermometer registers 200° C. 
Rice screenings and brewers' rice.— For each of these use the spe- 
cial double-walled flask with 100 grams of rice screenings, or brewers' 
rice, as the case may be, and 150 cubic centimeters of oil in the inner 
flask and 150 cubic centimeters between the walls. Extinguish the 
flame when the thermometer reaches 200° C. The oil in the inner 
flask should reach 200° C. in 26 minutes. 
Eye. — Use 100 grams of grain and 150 cubic centimeters of oil. 
Place a glass-wool pad, 2 inches in diameter and y± inch thick, in the 
bottom of the flask, taking care not to disturb it when putting in 
the grain and oil. Extinguish the flame when the thermometer 
registers 175° C. 
Soybeans. — Use 100 grams of soybeans and 150 cubic centimeters 
of oil, and extinguish the flame when the thermometer registers 
175° C. 
Wheat. — Use 100 grams of grain and 150 cubic centimeters of oil, 
and extinguish the flame when the thermometer registers 180° C. 
Wheat flour. — Use the double-wall flask with 150 cubic centimeters 
of oil in the inner flask and 150 cubic centimeters of oil between the 
walls, and 50 grams of flour. Extinguish the flame when the ther- 
mometer reaches 190° C. Use the special 16-cubic centimeter gradu- 
ate or, if the regular graduate is used, double the moisture test read- 
ing. The oil in the inner flask should reach 190° C. in 30 minutes. 
Tabulative specifications and special points for consideration are 
given in the summary on page 42. 
STANDARDIZING THE MOISTURE TESTER 
The earlier directions for operating the Brown-Duvel moisture 
tester called for adjusting the flame so that it would require about 
20 minutes to reach the temperature prescribed for the substance 
being tested. This required the constant attention of the operator, 
with frequent adjustments of the air and gas valves on the burners, 
while the moisture tests were being made. At intervals the tests 
would be running too rapidly, at other times' not fast enough. Sev- 
eral years of observation have shown that these recommendations 
have frequently been overlooked. Often when tests are started, no 
further attention is given them until the flame is extinguished when 
the temperature prescribed for the substance being tested is reached, 
regardless of whether it took the right number of minutes or not. 
This leads to irregular results. 
Errors resulting from incorrect heating time are illustrated in 
Figure 17, wherein the heating time has been varied with tests on 
different portions of the same sample, with the result that the 
moisture obtained from a sample of wheat varied by as much as 0.4 
per cent. The data further showed that, other things being equal, 
as the heating time of the moisture test increased beyond the correct 
number of minutes, there was a corresponding decrease in moisture- 
test results. Furthermore, if the heating time was fast, the moisture 
